I ought to let some one English answer this one but the Elliots as only Baronets do not qualify as Aristocrats..that is a large part of the humor in their vanity. Without a huge lot of money a girl would have to be remarkable in some other way to expect to marry into the nobility and there would hardly be enough Baronets to go round. I imagine that Mary with no more prospects than Anne had is perfectly content with her marriage to the the eldest son of the richest local family other han her own....unless Anne manages to do better. She would expect Elizabeth to do so. We havent seen any actual interaction between Mary and her father and eldest sister so we can only guess what it is.